resolved circular dependency between libevm and libevmjit

libevmjit/VM.cpp

@@ -2,6 +2,7 @@
 #include "VM.h"
 
 #include <libevm/VMFace.h>
+#include <libevm/VM.h>
 
 #include "ExecutionEngine.h"
 #include "Compiler.h"

libevmjit/VM.h

@@ -9,6 +9,9 @@ namespace dev
 {
 namespace eth
 {
+
+class VMFactory;
+
 namespace jit
 {
 
@@ -16,8 +19,11 @@ class VM: public VMFace
 {
 	virtual bytesConstRef go(ExtVMFace& _ext, OnOpFunc const& _onOp = {}, uint64_t _steps = (uint64_t)-1) override final;
 
+	enum Kind: bool { Interpreter, JIT };
+	static std::unique_ptr<VMFace> create(Kind, u256 _gas = 0);
+
 private:
-	friend VMFace;
+	friend VMFactory;
 	explicit VM(u256 _gas = 0): VMFace(_gas) {}
 
 	bytes m_output;